1. Field of the Invention
The present invention relates to an ink tank provided with a memory, a printing apparatus to use the ink tank and a used amount of ink monitoring system.
2. Description of the Related Art
Recently, a technology relating to the coloring (multi-coloring) of the image has so progressed that a printing apparatus using inks of a plurality of colors and a multi-color input apparatus is increasing in the market. Especially, an ink-jet printing apparatus, for its advantages such as low noise, low manufacturing cost, low running cost, adaptability for greater compactness, has come to be used widely as a printing apparatus or a copying machine or the like.
Conventionally, the kinds of ink tanks designed to be capable of having information about a remaining amount of ink in a replaceable (or interchangeable) ink tank have been proposed (see Japanese Patent Application Laid-open Nos. 2002-86709 and 6-126981 (1994)). More particularly, each of such ink tanks is provided with a memory element capable of storing the information about the remaining amount of the ink in the tank. Further, both Japanese Patent Application Laid-open Nos. 2002-86709 and 6-126981 (1994) respectively disclose a function for enabling the user of the printing apparatus to obtain an information about the remaining amount of the ink or the presence or absence of the remaining ink.
The printing apparatus, having the construction as is described above, is provided with a function for measuring the remaining amount of the ink in the ink tank in a range of the amount of usable ink normally taken from the ink tank (hereinafter referred to as “standard amount of the ink”). With such a type of printing apparatus, when the ink is used exceeding the range of the standard amount of the ink, the remaining amount of the ink is not measured and such remaining amount of the ink is not stored in the memory element of the ink tank, and these measuring and storing are not necessary.
In practice, however, there occurs a variance in the remaining amount of the ink in the tank owing to a variance resulting from the manufacturing process of the ink tank or a variance resulting from the operating condition of the printing apparatus, and so there is the possibility that the ink actually remains in the tank even when the remaining amount of the ink detected by the printing apparatus is “0”. In the case of the printing apparatus such as one described above, therefore, it actually can occur that the ink remaining in the tank is left unused where the printing apparatus is designed so that printing operation is discontinued when the remaining amount of the ink in the tank is detected as being “0” by the printing apparatus.
Further, if the user refills the ink tank, in which the amount of remaining ink came to decrease, with the ink purchased from the supplier other than the original supplier, the printing apparatus will become unable to measure the actually used amount of the ink from the amount of the ink remaining in the tank.